中文摘要：

实时监测功率变流器中直流母线电容的老化状态,及时发现并更换存在缺陷的直流母线电容,对提高功率变换器的可靠性具有重要意义。该文提出一种基于短路电流的大功率交流变流器直流母线电容等效串联电阻（equivalent series resistance,ESR）的在线监测方法,能准确的对直流母线电容ESR进行在线监测。首先对在线监测原理进行了详细分析,然后分析了短路测试对变流器正常工作的影响,最后,搭建了一台2k W的单相DC/AC逆变器实验样机,在不同工况下对直流母线电容的ESR进行了在线测试。试验结果表明,该方法能准确地在线监测出直流母线电容的ESR,简单有效。该方法可应用于大功率单相或三相变流器中且基本不受工况的限制。

英文摘要：

Finding and replacing the degraded capacitor timely by online monitoring the ageing state of capacitor can greatly improve the reliability of power converter. This paper presented an online condition monitoring method of ESR for DC-link capacitor of high-power AC converter based on short-circuit current, which can accurately measure the equivalent series resistance （ESR） of DC-link capacitor during the normal operation of power converter. The theory of online monitoring for DC-link capacitor was introduced in detail at first. Then, the influence of short-circuit test on the operation of power converter was discussed. Finally, the ESR of DC-link capacitor in a 2kW single-phase DC/AC converter was tested online by the online monitoring method proposed in this paper, and the ESR of DC-link capacitor can be accurately measured by this method. This method is suitable for single-phase or three-phase DC/AC, AC/DC, or AC/DC/AC power converters, and will not limited ,by the operation conditions of power converter.